西南岩溶石山地区岩溶地下水示踪试验与分析——以湖南湘西大龙洞为例

Analysis and tracing-test to karst groundwater in Southwest China karst rocky mountain area——A case study in Dalongdong, western Hunan

围绕大龙洞水库成库条件调查中存在的疑点问题开展示踪工作。根据示踪试验区的水文地质条件,选择降雨时地表水向地下集中渗漏排泄的狗肉寨极乐村洼地落水洞作为投放点,并在极乐村洼地落水洞的北东大龙洞地下河出口附近的鬼冲地下河、鬼冲泉和大龙洞地下河出口下方对岸100m处的Y034季节性水点(表层带岩溶泉点)及大龙洞地下河出口设置接收点,采用弱酸性红A荧光染料类试剂作示踪材料。示踪结果显示,鬼冲地下河、鬼冲泉和大龙洞地下河与投放点的连通性差;季节性水点Y034与投放点的连通性好;表明通过狗肉寨极乐村洼地落水洞汇集转化成的岩溶地下水与表层岩溶带季节性岩溶泉水水力联系密切,而与鬼冲地下河、大龙洞地下河之间则存在有地下分水岭。

In dealing with the questionable point in the investigation on the leakage problem of Dalongdong reservoir, the tracing-test is carried out. According to hydrogeological conditions, Jile sinkhole in Gourouzhai village is selected as a injection point for tracing during surface water flowing into underground after rainfall; and 4 collecting points, Guichong subterranean stream, Guichong spring, Spring Y034 and Dalongdong subterranean river outlet, are set. Weak acidic scarlet A fluoresce dye tracer is used with the continuous injection method . The test results indicate that the connectivity from injection point to Guichong subterranean stream, Guichong spring and Dalongdong subterranean river is not good, but between the seasonal spring Y034 and the injection point it is smoothly connected. It shows that the surface water is in contact with Guichong epikarst spring water through sinkhole, and there is a watershed between Guichong subterranean stream system and Dalongdong subterranean river system.